title: Simple sheath flow reactor for post-column fluorescence derivatization in capillary electrophoresis.
abstract: A system for post-column fluorescence derivatization in capillary electrophoresis is described. The post-column reactor uses a sheath flow detection cell where the reagents, o-phthaldialdehyde and beta-mercaptoethanol, are added to the sheath buffer and mix by diffusion with the analytes effusing from the separation capillary. Reaction progress is monitored and optimized by imaging a large portion of the sheath flow cuvette using an extended UV source and a CCD camera. Significantly, this design provides the ability to switch between the analysis of pre- and post-column derivatized amino acids and peptides easily and without sacrificing system performance. The lack of turbulent flow in this system minimizes post-separation band broadening. The limit of detection for glycine is 9.4 x 10(-8) M (110 amol) with a separation efficiency of 190,000 theoretical plates, without stacking. The performance of the system for a series of amino acids was evaluated using post-column and pre-capillary derivatization.
authors.affiliation: Department of Chemistry, University of Illinois at Urbana-Champaign 61801, USA.
authors.forename: K E
authors.initials: KE
authors.lastname: Oldenburg
authors.forename: X
authors.initials: X
authors.lastname: Xi
authors.forename: J V
authors.initials: JV
authors.lastname: Sweedler
mesh_terms: D000596:Amino Acids / Q000032:analysis*; D019075:Electrophoresis, Capillary; D017022:Flow Injection Analysis; D005453:Fluorescence; D010455:Peptides / Q000032:analysis*
chemical_list: D000596:Amino Acids; D010455:Peptides